Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752448AbaAXK5s (ORCPT ); Fri, 24 Jan 2014 05:57:48 -0500 Received: from smtp.citrix.com ([66.165.176.89]:25569 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751555AbaAXK5q (ORCPT ); Fri, 24 Jan 2014 05:57:46 -0500 X-IronPort-AV: E=Sophos;i="4.95,712,1384300800"; d="scan'208";a="96121406" Message-ID: <52E24727.6090809@citrix.com> Date: Fri, 24 Jan 2014 10:57:43 +0000 From: David Vrabel User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.16) Gecko/20121215 Iceowl/1.0b1 Icedove/3.0.11 MIME-Version: 1.0 To: Matt Wilson CC: Zoltan Kiss , , , , , , Anthony Liguori , , Matt Wilson Subject: Re: [Xen-devel] [PATCH v6] xen/grant-table: Avoid m2p_override during mapping References: <1390512224-27296-1-git-send-email-zoltan.kiss@citrix.com> <20140124054828.GA18522@u109add4315675089e695.ant.amazon.com> In-Reply-To: <20140124054828.GA18522@u109add4315675089e695.ant.amazon.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.80.2.76] X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 24/01/14 05:48, Matt Wilson wrote: > On Thu, Jan 23, 2014 at 09:23:44PM +0000, Zoltan Kiss wrote: >> The grant mapping API does m2p_override unnecessarily: only gntdev needs it, >> for blkback and future netback patches it just cause a lock contention, as >> those pages never go to userspace. Therefore this series does the following: >> - the original functions were renamed to __gnttab_[un]map_refs, with a new >> parameter m2p_override >> - based on m2p_override either they follow the original behaviour, or just set >> the private flag and call set_phys_to_machine >> - gnttab_[un]map_refs are now a wrapper to call __gnttab_[un]map_refs with >> m2p_override false >> - a new function gnttab_[un]map_refs_userspace provides the old behaviour >> >> It also removes a stray space from page.h and change ret to 0 if >> XENFEAT_auto_translated_physmap, as that is the only possible return value >> there. >> >> v2: >> - move the storing of the old mfn in page->index to gnttab_map_refs >> - move the function header update to a separate patch >> >> v3: >> - a new approach to retain old behaviour where it needed >> - squash the patches into one >> >> v4: >> - move out the common bits from m2p* functions, and pass pfn/mfn as parameter >> - clear page->private before doing anything with the page, so m2p_find_override >> won't race with this >> >> v5: >> - change return value handling in __gnttab_[un]map_refs >> - remove a stray space in page.h >> - add detail why ret = 0 now at some places >> >> v6: >> - don't pass pfn to m2p* functions, just get it locally >> >> Signed-off-by: Zoltan Kiss >> Suggested-by: David Vrabel > > Apologies for coming in late on this thread. I'm quite behind on > xen-devel mail that isn't CC: to me. > > It seems to have been forgotten that Anthony and I proposed a similar > change last November. > > https://lkml.kernel.org/r/1384307336-5328-1-git-send-email-anthony@codemonkey.ws > > Or am I misunderstanding the change? Yes, it's equivalent. There doesn't seem to have been a follow up patch posted for Anthony's patch so it's not surprising that it's fallen through the cracks. David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/